Packing.



PATENT OFFICE.

PAUL H. A. LEDER, or BALTIMORE, MARYLAND.

PACKING.

' SPECIFICATION forming part of Letters Patent No. 636,818, datedNovember 14, 1899. Application filed September 2, 1899. Serial No.729,383. (ll'o specimens.)

To all whom it may concern/.-

Be it known that 1, PAUL H. A. LEDER, a subject of the Emperor ofGermany, residing at Baltimore, in the State of Maryland, have inventedcertain new and useful Improvements in Packing; and I do hereby declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

My invention relates to packing which, although available for obtainingfluid tight joints generally, is more particularly designed as a meansfor providing a fluid-tight closure for bottles, jars, and similarvessels containing beverages and food products.

Heretofore cork and rubber have generally been used for the purposesstated. Both sub stances have, however, inherent disadvantages. Theformer, cork, in that it is readily attacked by acids such as aregenerally present in food products, is quite readily decomposed and thenliable to impart a very disagreeable smell andtaste t0 substancescontained in the vessel closed thereby. Rubber has likewise thedisadvantage of imparting a disagreeable taste and smell to substancesin contact therewith and although not as readily affected by acids isnevertheless very perishable when exposed to atmospheric in fluences.

A stopper or other packing serving the pur poses referred to andobviating the disadvantages inherent to cork and rubber and othersealing substances heretofore used should j therefore possess therequired degree of elasticity, it should be acid-proof and proof againstatmospheric influences and comparatively high temperatures, it should beimpermeable by liquids and gases and indifferent to their action, and,finally, it shouldbeboth tasteless and odorless.

My invention has for its object the production of a packing possessingall the properties last referred to, and in carrying out my invention Iuse asbestos fibers in a more or less finely divided state,felted orotherwise united, as by means of a solution of silicate of magnesia, andmolded or otherwise formed to the desired shape by pressure, so as toleave a comparatively porous more or less elastic body. Such a substanceor body is odorless lose acting as a waterproofing'agent withoutimpairing the elasticity of the asbestos body. The volatile solvent isthen allowed to evaporate or is driven off by heat and may be recoveredby well-known means. On the other hand, I can use asbestos fibers,saturate the same with a solution of cellulose, and then form thestopper or other packing from this composition by well-knownmeansresorted to in plastics. The stopper or other packing may then be used,though I prefer, not only for the purpose of increasing itsimpermeability, but also With a view to impart to the finished productsmooth surfaces, thereby decreasing its liability to stick andfacilitating the fashioning thereof, to impregnate the cellnlosesaturated asbestos fibers with a solution of paraffin in a Volatilesolvent-as, for instance, ordinary gasolene-this solvent being likewiseallowed to evaporate or being driven off by heat.

Although the paraffin increases the impermeability of the product byliquids and gases, is odorless and tasteless, is unaffected by suchacids as are generally present in many food products, and is unaffectedby comparatively high temperatures or atmospheric influences, it doesnot in the least impair the elasticity or compressibility of theproduct, and when the latter is used as a packing for moving machineelements it is in a measure self-lubricating.

Notwithstanding the fact that the packing ing as the final product is tobe of a greater or less density may be felted into the form of thinsheets in a paper-making machine. A number of these sheets,according tothe thickness of the final product, are then laid one upon another andsubjected to pressure, and from this thick sheet the packing to beobtained is then stamped out, as disks, rings, or gaskets, &c., whichare afterward succes' sively treated with cellulose and paraffin, or thethick sheet may first be saturated or impregnated with cellulose andthen with paraffin, or if the final product is to be of considerablethickness a greater or less number of the thin sheets may be treatedwith cellulose and paraffin and interposed between sheets not sotreated, the thick sheet being subsequently treated with cellulose andparaflin before or after compression; or the packing may be made of anyso-called asbestos cement, so long as the constituents thereof are ofsuch a character that the final product will have the propertiesdescribed.

I am aware that it has been proposed to waterproof fabrics, among othersasbestos fabrics, by treating such with a nitrocellulose; and I am alsoaware that paper has been waterproofed by treating the same withparafiin, and I do not desire to claim broadly either treatment per so.It will, however, be readily understood that a fabric, even an asbestosfabric treated with nitrocellulose, would not be available as a packingserving the purposes and having the properties described, and, as iswell known, paper treated with paraffin will not serve the purposes ofpacking.

